From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 19 Aug 2001 16:56:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 19 Aug 2001 16:56:32 -0400 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:54825 "EHLO flinx.biederman.org") by vger.kernel.org with ESMTP id ; Sun, 19 Aug 2001 16:56:25 -0400 To: esr@thyrsus.com Cc: Linux Kernel List , gars@lanm-pc.com Subject: Re: Swap size for a machine with 2GB of memory In-Reply-To: <20010819024233.A26916@thyrsus.com> From: ebiederm@xmission.com (Eric W. Biederman) Date: 19 Aug 2001 14:49:23 -0600 In-Reply-To: <20010819024233.A26916@thyrsus.com> Message-ID: User-Agent: Gnus/5.0808 (Gnus v5.8.8) Emacs/20.5 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org "Eric S. Raymond" writes: > The Red Hat installation manual claims that the size of the swap partition > should be twice the size of physical memory, but no more than 128MB. > > The screaming hotrod machine Gary Sandine and I built around the Tyan S2464 > has 2GB of physical memory. Should I believe the above formula? If not, > is there a more correct one for calculating needed swap on machines with > very large memory? There is no magic formula for calculating the amount of swap space needed. It really needs to be sized to the expected load on your box plus some. If you seriously expect to be using swap, have swapsize > memsize and figure the amount of virtual memory you have is swapsize. With respect to swap partitions the current limit is about 64Gig. You can actually make a larger swap partition but the kernel on x86 only uses 24 offset bits into that partition. The 128MB partition existed but was removed long ago. Eric